Abstract: A new adaptive backstepping controller is proposed for a hypersonic vehicle with limited angle-of-attack(AOA). Firstly, the vehicle model is rewritten into a strict-feedback form so that backstepping can be employed in the design process. Then a smooth saturation function is introduced to restrict the nominal AOA into the prescribed range and the filtered signal remains differentiable. Moreover, the filtering error is compensated with an auxiliary system. Further, the asymmetric time-varying barrier function is utilized to constrain the virtual AOA command. Regarding the uncertainties and disturbances, the novel adaptive laws are built to estimate the upper bounds of the lumped disturbances. Finally, the stability of the closed-loop system is proved based on the Lyapunov theory. All the signals are uniformly ultimate bounded and time-varying AOA constraint is guaranteed. The simulation results show that the proposed controller can guarantee good tracking performances with limited AOA.

Key words: Hypersonic vehicle, Limited angle-of-attack (AOA), Asymmetric barrier function, Adaptive control, Backstepping